Summary

After analyzing and fitting data scraped from Kicks on Fire and StockX to a multi-linear regression model, this analysis answered the following inferential questions: -Which of the variables appears to be the best covariate for explaining sneaker resale values? -What is the likely range for the difference in resale values for collaborated and non-collaborated sneakers? -Is there any evidence that the association between sentiment and resale values differ by collaborations? -Are there other interesting associations with resale values that are worth mentioning and modeling? Ultimately, it was determined that the log of the resale price of a sneaker was the most important factor in determining the resale value of a sneaker. Additionally,

Introduction

Using data scraped from a sneaker news website, Kicks on Fire, and StockX, a resale marketplace for Sneakers, the aim of this analysis is to understand what factors effect a sneaker’s resale value. The dataset contains over 6000 sneakers released over the past decade with their average resale value after two plus months of initial release. Additional features such as is a sneaker a collaboration, the intended sex for the sneaker release, if a sneaker was retro, or if it is a kids shoe were engineered using regular expressions. The color of a sneaker was also assigned using a vector representation of the colorway string and getting the cosine similiarity of that vector with common colors to determine the “main color” of a sneaker.

Ultimately, this analysis will answer inferential questions such as which variable is the biggest contributor to a sneaker’s resale values, a likely range for differences in resale values for collab and non-collab sneakers, and potential evidence of associations, in particular, between sentiment and resale values differing by collaborations. To answer these questions posed, this analysis will the explore and transform the data, fit multi-linear regression models with appropriate features, and interpret the results.

Exploratory Data Analysis (EDA)

Data Transformation

Before beginning the analysis, the number of null values in the dataset were counted. Although there were no null values found in the predictors, there were 181 rows in the response variable missing values. This was likely due to the scraper unable to find those sneakers on StockX. Ultimately, these rows were removed instead of imputed since they accounted for less than 3% of the entire dataset and it wasn’t apparent if they weren’t on StockX or if they were difficult to find when searching for them. After removing those rows, the final dataset contained 6,164 unique observations and 19 rows, albeit, 5 of them being intermediate columns or text descriptions.

Since one of the assumptions of a linear model is normality, the distribution of the response variable was plotted as a histogram. The distribution of Resale prices were heavily skewed left, and therefore multiple transformation were performed. Ultimately, the log transformation was deemed to have the best resemblance to a normal distribution. Therefore, the log transformation of the response variable was used for the rest of the analysis.

The “wants” column scraped from Kicks on Fire is akin to a like button, and therefore could be used as a proxy for public sentiment towards each sneaker. The distribution of “wants” was heavily skewed left with a wide range of values. Due to this, and since many sneakers had values of equal to zero, “wants” was binned into four groups roughly representing the quartiles of values in the “wants” columns. A sneaker with less than 50 “wants” was considered “Not Popular”, greater than equal to 50 but less than 250 was “Somewhat Popular”, greater than or equal to 250 and less than 1000 was “Very Popular”, and greater than or equal to “1000” was “Extremely Popular”. The figure on the left below visualizes the distribution of each category below.

Data Visualization

Due to our interest in finding evidence between an association between sentiment and resale values by by whether or not a sneaker was collaborated on, the plot on the right visualizes that relationship. This revealed that there does appears to be a difference in resale values among each popularity group when collaborated on versus not. Although the resale distributions for non-collaborated sneakers look similar to the overall distribution of the data set (pictured left), the distributions for sneakers that were collaborated do not. The median resale values for “Somewhat Popular” and “Very Popular” collaborated sneakers appear to be roughly the same, as compared to before. The median value and distribution of extremely popular, collab sneakers, seem to be higher than before as well.

Two additional associations found while performing EDA can be seen in the plot below. The graph on the left shows the log of resale prices versus retail prices split by brand. From this chart, we can make out that some brands, such as Converse, Nike, Air Jordan, and Adidas, all appear to have strong positive correlations between the two variables. Meanwhile, some brands such as Puma and Asics, have relatively flat slopes with no correlation between the two variables. The second graph on the right depicts the log of resale prices versus sneaker color split by collaboration. The resale value medians and distributions for each colors vary a lot more sneakers for sneakers that are collaborated on versus not. In particular, the resale value distributions for brown, purple, red, and white sneakers seem to be a lot higher when collaborated on, while the distribution for gray sneakers seems to decrease. Both of these associations will be tested for statistical significance when modeling.

Model

Model Selection

The final model was selecting based on our findings from the EDA, step-wise model selection, and ANOVA f-tests. When checking model diagnostic plots, it was determined that the log transformation of the retail value for each sneaker would create more randomness among the residuals in the residuals vs fitted plots and was necessary to satisfy the linearity assumption. The rest of the variables were all categorical, and therefore no other transformations to predictors were made. The final model took the form: \(y_i = \beta_0 + \beta_1 Brand + \beta_2 Release Month + \beta_3 Release Day + \beta_4 Sex + \beta_5 Collab + \beta_6 Retro + \beta_7 Kids + \beta_8 Color + \beta_9 BinWants + \beta_{10} log(RetailPrice) + \beta_{11} (BinWants:Collab) + \beta_{12} (log(RetailPrice):Brand) + \beta_{13} (Collab:Color)\)

The final model summary can be seen below. Since the response variable is the log of resale values, it is important to exponentiate the coefficients before interpreting the model.

The model’s intercept is 15.21, which means that, if all variables are set to 0 or their respective baseline, the average resale price of a sneaker would be $15.21. The intercept is also statistically significant as its’ p-value is smaller than 0.05. The adjusted r-squared value for the model is ~0.38, which means about 38% of variability in the dataset can be explained by the variables in our model.

We can also determine that the log of the sneaker’s retail price is the best covariate for explaining sneaker resale values. This is because predictors with higher absolute t-values indicate greater evidence against the null hypothesis and importance in predicting the response variable. The coefficient of this covariate indicates that for every additional increase in the log of the retail price, the resale value, on average, for a sneaker increases by $1.48, holding all other variables constant.

For this analysis, only variables that had p-values lower than the 0.05 level were deemed to be statistically significant. Therefore, brand, release month, release day, retro, “wants” binned, log of retail price, the interaction between brand and the log of retail price, the interaction between collab and “wants” binned, and the interaction between collab and main color were all statistically significant variables.

Additionally, since the interaction between collaborations and “wants” binned was statistically significant, we know that there is evidence of an association between sentiment and resale values different. For the interaction, non-collaborated sneakers and “Not Popular” were the model’s baseline. The statistically significant effects of this interaction can be interpreted as, if all other variables are held constant, on average, for sneakers that were collaborated on and were “Somewhat Popular”, the average resale price of a sneaker increased by $1.13 compared to the model baseline. For the same conditions, on average, sneakers that were collaborated on and were “Extremely Popular”, the average resale price of a sneaker increased by $1.69 compared to the model baseline. Although not statistically significant on the 0.05 level, holding all variables constant, sneakers that were collaborated on and were “Very Popular”, the average resale price of a sneaker increased by $1.12 compared to the model baseline.

  2.5 % 97.5 %
collabTRUE 0.9619 1.2

Next, a likely range for the difference in sneaker resale values for sneakers that were non-collab and collab can be found by getting the 95% confidence interval of the collab variable in the final model, which can be seen above. Based on the 95% confidence interval for the variable collab, if all other variables are held constant, the average resale price of a collab sneaker increases by $0.96 to $1.20 compared non-collab sneakers. It is worth noting that collab was not found to be significant on its own, but was significant in its interaction between sneaker sentiment and color.

term estimate std.error statistic p.value
(Intercept) 2.7220249 0.1309938 20.7797938 0.0000000
brandAir Jordan -1.4736253 0.2795425 -5.2715610 0.0000001
brandAsics 5.8292930 3.9994977 1.4575063 0.1450282
brandConverse -3.8826690 1.9132581 -2.0293493 0.0424661
brandJordan Brand -1.0193292 0.6562504 -1.5532626 0.1204123
brandNew Balance -3.7749322 2.5269023 -1.4938972 0.1352543
brandNike -1.7853927 0.1626169 -10.9791346 0.0000000
brandNike Basketball -2.1295007 0.7247864 -2.9381078 0.0033146
brandNike Running -0.9793677 1.2241818 -0.8000182 0.4237314
brandOther Brands 0.0420777 0.9012705 0.0466871 0.9627641
brandPuma 0.0597020 1.0646902 0.0560746 0.9552843
brandReebok -0.2161552 0.8269331 -0.2613938 0.7937977
release_monthFeb 0.0263528 0.0289974 0.9087966 0.3634935
release_monthMar 0.0787506 0.0289739 2.7179847 0.0065867
release_monthApr 0.0246435 0.0294154 0.8377768 0.4021889
release_monthMay -0.0198294 0.0307540 -0.6447755 0.5190969
release_monthJun 0.0413382 0.0297805 1.3880963 0.1651585
release_monthJul 0.0167872 0.0303453 0.5532063 0.5801424
release_monthAug 0.0262351 0.0299913 0.8747593 0.3817394
release_monthSep 0.0685826 0.0309396 2.2166588 0.0266832
release_monthOct 0.0401937 0.0316186 1.2712069 0.2037036
release_monthNov 0.0872633 0.0299581 2.9128457 0.0035945
release_monthDec 0.0826664 0.0303689 2.7220703 0.0065059
release_dowMonday 0.1008594 0.0351539 2.8690810 0.0041308
release_dowTuesday 0.0225498 0.0327940 0.6876176 0.4917198
release_dowWednesday 0.0251268 0.0300584 0.8359345 0.4032245
release_dowThursday -0.0109732 0.0266154 -0.4122877 0.6801431
release_dowFriday 0.0091321 0.0278366 0.3280599 0.7428777
release_dowSaturday 0.0359227 0.0270957 1.3257686 0.1849660
wmnsTRUE 0.0262820 0.0160629 1.6361880 0.1018519
collabTRUE 0.0716579 0.0563916 1.2707185 0.2038773
retroTRUE 0.1620268 0.0323543 5.0078971 0.0000006
kidsTRUE -0.0153924 0.0228705 -0.6730217 0.5009590
main_colorBlue 0.0062015 0.0170300 0.3641490 0.7157594
main_colorBrown -0.0273718 0.0381856 -0.7168096 0.4735190
main_colorGray -0.0098409 0.0280986 -0.3502283 0.7261795
main_colorGreen -0.0021702 0.0386206 -0.0561918 0.9551909
main_colorMulti-Color 0.0833139 0.0425781 1.9567304 0.0504248
main_colorOrange -0.0628058 0.0384314 -1.6342321 0.1022618
main_colorPurple -0.0292959 0.0369776 -0.7922620 0.4282388
main_colorRed 0.0083963 0.0238334 0.3522905 0.7246326
main_colorWhite 0.0147409 0.0150038 0.9824734 0.3259057
main_colorYellow -0.0972134 0.0730376 -1.3310053 0.1832371
bin_wantsSomewhat Popular -0.0248405 0.0176301 -1.4089882 0.1588897
bin_wantsVery Popular 0.0494566 0.0183010 2.7023988 0.0069032
bin_wantsExtremely Popular 0.1771991 0.0199648 8.8755807 0.0000000
log_retail_price 0.3921911 0.0263512 14.8832570 0.0000000
collabTRUE:bin_wantsSomewhat Popular 0.1199308 0.0592720 2.0233968 0.0430758
collabTRUE:bin_wantsVery Popular 0.1120288 0.0585095 1.9147114 0.0555761
collabTRUE:bin_wantsExtremely Popular 0.5248961 0.0615767 8.5242597 0.0000000
brandAir Jordan:log_retail_price 0.3238057 0.0553798 5.8470028 0.0000000
brandAsics:log_retail_price -1.1940970 0.7962466 -1.4996572 0.1337550
brandConverse:log_retail_price 0.8384674 0.4181146 2.0053531 0.0449695
brandJordan Brand:log_retail_price 0.1898603 0.1341948 1.4148115 0.1571749
brandNew Balance:log_retail_price 0.7353419 0.4998966 1.4709880 0.1413460
brandNike:log_retail_price 0.3736445 0.0333368 11.2081817 0.0000000
brandNike Basketball:log_retail_price 0.4352096 0.1406644 3.0939576 0.0019840
brandNike Running:log_retail_price 0.2321527 0.2520508 0.9210552 0.3570581
brandOther Brands:log_retail_price -0.0127406 0.1849630 -0.0688816 0.9450861
brandPuma:log_retail_price -0.0637214 0.2202884 -0.2892636 0.7723895
brandReebok:log_retail_price 0.0502490 0.1679321 0.2992225 0.7647805
collabTRUE:main_colorBlue -0.0863874 0.0534528 -1.6161427 0.1061152
collabTRUE:main_colorBrown -0.0258520 0.0913443 -0.2830168 0.7771736
collabTRUE:main_colorGray -0.3347995 0.1242360 -2.6948667 0.0070610
collabTRUE:main_colorGreen 0.1345769 0.1236725 1.0881715 0.2765624
collabTRUE:main_colorMulti-Color -0.0872436 0.1087129 -0.8025135 0.4222873
collabTRUE:main_colorOrange 0.1608573 0.0918387 1.7515207 0.0799066
collabTRUE:main_colorPurple 0.0550746 0.1054543 0.5222600 0.6015083
collabTRUE:main_colorRed 0.0709415 0.0834196 0.8504179 0.3951262
collabTRUE:main_colorWhite 0.1100795 0.0470256 2.3408402 0.0192725
collabTRUE:main_colorYellow 0.0453065 0.1552968 0.2917414 0.7704943
Model Assesment

The model diagnostics were the plotted below. Looking at the residuals vs. fitted plot, the model does seem to satisfy the independence and equal variance assumptions as the data points are randomly scattered throughout the plot and the red line indicating trends is straight.

The Normal Q-Q plot indicates whether or not the assumption of Normality is violated by the model. Looking at the plot, the points roughly lie on the dashed line drawn, until the right most extremity. This is likely due to the long right tail of the response variable distribution. Therefore, the normality assumption does appear to be satisfied.

Potential outliers, leverage points, or highly influential points can all be identified using the Residuals vs. Leverage plot below. From the Cook’s distance lines, there are no highly influential data points as there are not values with a Cook’s distance value greater than 0.5 or 1. This meant no data points were highly influential and did not need to be removed from our analysis. High leverage points were calculated using the formula \(2*(p+1)/n\). From this threshold there were quite a few high leverage points. Outliers could also be identified from the Residuals vs. Leverage plot below by looking at the y-values of the data points in the graph. The distribution of data points appear to follow a normal distribution and can be found between 3 and -3 standard deviations. However, there are quite a few data points that are outside those metrics.

Finally, the Variance Inflation Factor (VIF) score for each variable in the model was calculated to determine how much multicollinearity between the variables in the model was inflating the variance of the regression coefficient for each variable. However, since the only continuous variable was the log of the retail price, that was the only VIF score worth noting. The log of the retail price had a VIF score of 3.31, and therefore we can safely say it’s not correlated with other variables because it’s lower than the high correlation threshold of 10.

Conclusion

In conclusion, our analysis determined that the best covariate for explaining sneaker resale values was the log of the resale price. In general, the log of the resale price was positively correlated with resale values. Additionally, there was an association found between sentiment and resale values differing by collaborations. As discussed earlier, sneakers that were collaborated on and were “Somewhat Popular” or “Extremely Popular” usually had higher resale values than “Not Popular” and non-collab sneakers. There were also associations found between the log of the resale price and resale values differing by Brand, as well as the main color and resale values of sneakers differing by collaborations. Although collaborations were not found to be statistically significant, the likely difference in resale values for collaborated and non-collab sneakers was found to be between an increase in $0.96 to $1.20 for collab sneakers versus not.

Overall, there were a few limitations of this analysis. First, the dataset built from Kicks on Fire is not an exhaustive list of every sneaker ever released and is general biased towards talking about more “trendy” sneakers. Therefore, some brands may appear to only have sneakers with high resale values, such as Converse. Second, determining the main color for a sneaker is tough job for a human to label, let alone a computer. Although the labels seemed generally accurate, the main color of a sneaker is hard to quantify and up for debate. Third, although the response variable is an average resale price of sneakers, According to StockX there has been found to be a range of average prices between different shoe sizes of the same sneaker, which is something the model doesn’t take into account.

Appendix

III. EDA Distributions of response variable

Distributions of retail price

EDA for log resale vs brand

EDA for log resale vs main color

EDA for log resale vs release month

EDA for log resale vs release day

EDA for log resale vs binned “wants”

EDA for log resale vs log retail

Model

## 
## Call:
## lm(formula = log_resale_price ~ brand + release_month + release_dow + 
##     wmns + collab + retro + kids + main_color + bin_wants + retail_price, 
##     data = sneakers)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -2.5217 -0.2455 -0.0107  0.2084  3.7741 
## 
## Coefficients:
##                              Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                 4.0792824  0.0385592 105.793  < 2e-16 ***
## brandAir Jordan             0.1403510  0.0216334   6.488 9.40e-11 ***
## brandAsics                 -0.1597796  0.0901347  -1.773 0.076332 .  
## brandConverse              -0.0131283  0.0877316  -0.150 0.881052    
## brandJordan Brand          -0.0834422  0.0397535  -2.099 0.035859 *  
## brandNew Balance           -0.0980314  0.1314188  -0.746 0.455728    
## brandNike                   0.0523806  0.0144458   3.626 0.000290 ***
## brandNike Basketball        0.0401751  0.0404242   0.994 0.320342    
## brandNike Running           0.1332712  0.0776873   1.715 0.086308 .  
## brandOther Brands          -0.0214001  0.0455201  -0.470 0.638283    
## brandPuma                  -0.2229885  0.0594071  -3.754 0.000176 ***
## brandReebok                 0.0217633  0.0463381   0.470 0.638612    
## release_monthFeb            0.0214823  0.0297217   0.723 0.469842    
## release_monthMar            0.0553728  0.0296907   1.865 0.062231 .  
## release_monthApr            0.0200584  0.0301602   0.665 0.506036    
## release_monthMay           -0.0313537  0.0315031  -0.995 0.319650    
## release_monthJun            0.0292981  0.0304838   0.961 0.336539    
## release_monthJul           -0.0024515  0.0310468  -0.079 0.937066    
## release_monthAug            0.0223310  0.0307258   0.727 0.467386    
## release_monthSep            0.0661192  0.0317232   2.084 0.037178 *  
## release_monthOct            0.0424801  0.0324080   1.311 0.189978    
## release_monthNov            0.0910831  0.0306954   2.967 0.003016 ** 
## release_monthDec            0.0709438  0.0310805   2.283 0.022489 *  
## release_dowMonday           0.1773772  0.0358024   4.954 7.45e-07 ***
## release_dowTuesday          0.0686351  0.0332976   2.061 0.039320 *  
## release_dowWednesday        0.0626654  0.0306779   2.043 0.041126 *  
## release_dowThursday         0.0471950  0.0270069   1.748 0.080598 .  
## release_dowFriday           0.0443193  0.0283175   1.565 0.117614    
## release_dowSaturday         0.0783300  0.0276095   2.837 0.004568 ** 
## wmnsTRUE                    0.0331839  0.0164615   2.016 0.043860 *  
## collabTRUE                  0.2660243  0.0196380  13.546  < 2e-16 ***
## retroTRUE                   0.1481206  0.0330190   4.486 7.39e-06 ***
## kidsTRUE                   -0.0635748  0.0228878  -2.778 0.005492 ** 
## main_colorBlue              0.0018315  0.0165285   0.111 0.911770    
## main_colorBrown            -0.0623182  0.0355700  -1.752 0.079825 .  
## main_colorGray             -0.0096130  0.0280403  -0.343 0.731741    
## main_colorGreen             0.0159876  0.0376303   0.425 0.670954    
## main_colorMulti-Color       0.0612667  0.0401180   1.527 0.126772    
## main_colorOrange           -0.0287045  0.0356582  -0.805 0.420856    
## main_colorPurple           -0.0219321  0.0354176  -0.619 0.535780    
## main_colorRed               0.0214855  0.0234209   0.917 0.358989    
## main_colorWhite             0.0266488  0.0145803   1.828 0.067638 .  
## main_colorYellow           -0.0998767  0.0659459  -1.515 0.129944    
## bin_wantsSomewhat Popular   0.0126271  0.0170421   0.741 0.458763    
## bin_wantsVery Popular       0.1147260  0.0176036   6.517 7.74e-11 ***
## bin_wantsExtremely Popular  0.3037893  0.0192095  15.815  < 2e-16 ***
## retail_price                0.0033194  0.0001017  32.633  < 2e-16 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.4298 on 6117 degrees of freedom
## Multiple R-squared:  0.3494, Adjusted R-squared:  0.3445 
## F-statistic:  71.4 on 46 and 6117 DF,  p-value: < 2.2e-16

## 
## Call:
## lm(formula = log_resale_price ~ brand + release_month + release_dow + 
##     wmns + collab + retro + kids + main_color + bin_wants + log_retail_price, 
##     data = sneakers)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -1.7783 -0.2377 -0.0097  0.1857  3.9719 
## 
## Coefficients:
##                             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                 1.686911   0.089893  18.766  < 2e-16 ***
## brandAir Jordan             0.113248   0.021603   5.242 1.64e-07 ***
## brandAsics                 -0.200110   0.089656  -2.232 0.025652 *  
## brandConverse               0.020547   0.087356   0.235 0.814054    
## brandJordan Brand          -0.098477   0.039542  -2.490 0.012786 *  
## brandNew Balance           -0.123857   0.130756  -0.947 0.343554    
## brandNike                   0.040374   0.014372   2.809 0.004982 ** 
## brandNike Basketball        0.021146   0.040244   0.525 0.599295    
## brandNike Running           0.140815   0.077306   1.822 0.068574 .  
## brandOther Brands          -0.027090   0.045276  -0.598 0.549648    
## brandPuma                  -0.218746   0.059111  -3.701 0.000217 ***
## brandReebok                 0.004719   0.046078   0.102 0.918427    
## release_monthFeb            0.027915   0.029574   0.944 0.345255    
## release_monthMar            0.072354   0.029539   2.449 0.014334 *  
## release_monthApr            0.027865   0.030012   0.928 0.353194    
## release_monthMay           -0.027424   0.031348  -0.875 0.381706    
## release_monthJun            0.041084   0.030342   1.354 0.175780    
## release_monthJul            0.009847   0.030901   0.319 0.750007    
## release_monthAug            0.023808   0.030573   0.779 0.436170    
## release_monthSep            0.066245   0.031565   2.099 0.035884 *  
## release_monthOct            0.041892   0.032246   1.299 0.193949    
## release_monthNov            0.080164   0.030542   2.625 0.008693 ** 
## release_monthDec            0.070657   0.030926   2.285 0.022362 *  
## release_dowMonday           0.148086   0.035665   4.152 3.34e-05 ***
## release_dowTuesday          0.053595   0.033142   1.617 0.105901    
## release_dowWednesday        0.038266   0.030548   1.253 0.210373    
## release_dowThursday         0.020888   0.026910   0.776 0.437654    
## release_dowFriday           0.030982   0.028200   1.099 0.271962    
## release_dowSaturday         0.049302   0.027518   1.792 0.073235 .  
## wmnsTRUE                    0.029162   0.016375   1.781 0.074975 .  
## collabTRUE                  0.272387   0.019503  13.966  < 2e-16 ***
## retroTRUE                   0.147183   0.032850   4.481 7.58e-06 ***
## kidsTRUE                   -0.015373   0.023028  -0.668 0.504436    
## main_colorBlue             -0.002759   0.016447  -0.168 0.866763    
## main_colorBrown            -0.044499   0.035362  -1.258 0.208307    
## main_colorGray             -0.028693   0.027914  -1.028 0.304033    
## main_colorGreen             0.008407   0.037442   0.225 0.822342    
## main_colorMulti-Color       0.062279   0.039917   1.560 0.118761    
## main_colorOrange           -0.031986   0.035482  -0.901 0.367373    
## main_colorPurple           -0.024294   0.035242  -0.689 0.490634    
## main_colorRed               0.020981   0.023304   0.900 0.367993    
## main_colorWhite             0.023514   0.014504   1.621 0.105040    
## main_colorYellow           -0.110867   0.065620  -1.690 0.091169 .  
## bin_wantsSomewhat Popular  -0.031493   0.017210  -1.830 0.067315 .  
## bin_wantsVery Popular       0.053276   0.017934   2.971 0.002982 ** 
## bin_wantsExtremely Popular  0.242763   0.019599  12.387  < 2e-16 ***
## log_retail_price            0.598942   0.017763  33.719  < 2e-16 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.4276 on 6117 degrees of freedom
## Multiple R-squared:  0.3558, Adjusted R-squared:  0.351 
## F-statistic: 73.46 on 46 and 6117 DF,  p-value: < 2.2e-16

## 
## Call:
## lm(formula = log_resale_price ~ brand + release_month + release_dow + 
##     wmns + collab + retro + kids + main_color + bin_wants + log_retail_price + 
##     bin_wants:collab + log_retail_price:brand + collab:main_color, 
##     data = sneakers)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -1.6802 -0.2265  0.0077  0.1738  3.7662 
## 
## Coefficients:
##                                        Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                            2.722025   0.130994  20.780  < 2e-16 ***
## brandAir Jordan                       -1.473625   0.279543  -5.272 1.40e-07 ***
## brandAsics                             5.829293   3.999498   1.458  0.14503    
## brandConverse                         -3.882669   1.913258  -2.029  0.04247 *  
## brandJordan Brand                     -1.019329   0.656250  -1.553  0.12041    
## brandNew Balance                      -3.774932   2.526902  -1.494  0.13525    
## brandNike                             -1.785393   0.162617 -10.979  < 2e-16 ***
## brandNike Basketball                  -2.129501   0.724786  -2.938  0.00331 ** 
## brandNike Running                     -0.979368   1.224182  -0.800  0.42373    
## brandOther Brands                      0.042078   0.901270   0.047  0.96276    
## brandPuma                              0.059702   1.064690   0.056  0.95528    
## brandReebok                           -0.216155   0.826933  -0.261  0.79380    
## release_monthFeb                       0.026353   0.028997   0.909  0.36349    
## release_monthMar                       0.078751   0.028974   2.718  0.00659 ** 
## release_monthApr                       0.024644   0.029415   0.838  0.40219    
## release_monthMay                      -0.019829   0.030754  -0.645  0.51910    
## release_monthJun                       0.041338   0.029781   1.388  0.16516    
## release_monthJul                       0.016787   0.030345   0.553  0.58014    
## release_monthAug                       0.026235   0.029991   0.875  0.38174    
## release_monthSep                       0.068583   0.030940   2.217  0.02668 *  
## release_monthOct                       0.040194   0.031619   1.271  0.20370    
## release_monthNov                       0.087263   0.029958   2.913  0.00359 ** 
## release_monthDec                       0.082666   0.030369   2.722  0.00651 ** 
## release_dowMonday                      0.100859   0.035154   2.869  0.00413 ** 
## release_dowTuesday                     0.022550   0.032794   0.688  0.49172    
## release_dowWednesday                   0.025127   0.030058   0.836  0.40322    
## release_dowThursday                   -0.010973   0.026615  -0.412  0.68014    
## release_dowFriday                      0.009132   0.027837   0.328  0.74288    
## release_dowSaturday                    0.035923   0.027096   1.326  0.18497    
## wmnsTRUE                               0.026282   0.016063   1.636  0.10185    
## collabTRUE                             0.071658   0.056392   1.271  0.20388    
## retroTRUE                              0.162027   0.032354   5.008 5.66e-07 ***
## kidsTRUE                              -0.015392   0.022871  -0.673  0.50096    
## main_colorBlue                         0.006201   0.017030   0.364  0.71576    
## main_colorBrown                       -0.027372   0.038186  -0.717  0.47352    
## main_colorGray                        -0.009841   0.028099  -0.350  0.72618    
## main_colorGreen                       -0.002170   0.038621  -0.056  0.95519    
## main_colorMulti-Color                  0.083314   0.042578   1.957  0.05042 .  
## main_colorOrange                      -0.062806   0.038431  -1.634  0.10226    
## main_colorPurple                      -0.029296   0.036978  -0.792  0.42824    
## main_colorRed                          0.008396   0.023833   0.352  0.72463    
## main_colorWhite                        0.014741   0.015004   0.982  0.32591    
## main_colorYellow                      -0.097213   0.073038  -1.331  0.18324    
## bin_wantsSomewhat Popular             -0.024841   0.017630  -1.409  0.15889    
## bin_wantsVery Popular                  0.049457   0.018301   2.702  0.00690 ** 
## bin_wantsExtremely Popular             0.177199   0.019965   8.876  < 2e-16 ***
## log_retail_price                       0.392191   0.026351  14.883  < 2e-16 ***
## collabTRUE:bin_wantsSomewhat Popular   0.119931   0.059272   2.023  0.04308 *  
## collabTRUE:bin_wantsVery Popular       0.112029   0.058509   1.915  0.05558 .  
## collabTRUE:bin_wantsExtremely Popular  0.524896   0.061577   8.524  < 2e-16 ***
## brandAir Jordan:log_retail_price       0.323806   0.055380   5.847 5.26e-09 ***
## brandAsics:log_retail_price           -1.194097   0.796247  -1.500  0.13376    
## brandConverse:log_retail_price         0.838467   0.418115   2.005  0.04497 *  
## brandJordan Brand:log_retail_price     0.189860   0.134195   1.415  0.15717    
## brandNew Balance:log_retail_price      0.735342   0.499897   1.471  0.14135    
## brandNike:log_retail_price             0.373645   0.033337  11.208  < 2e-16 ***
## brandNike Basketball:log_retail_price  0.435210   0.140664   3.094  0.00198 ** 
## brandNike Running:log_retail_price     0.232153   0.252051   0.921  0.35706    
## brandOther Brands:log_retail_price    -0.012741   0.184963  -0.069  0.94509    
## brandPuma:log_retail_price            -0.063721   0.220288  -0.289  0.77239    
## brandReebok:log_retail_price           0.050249   0.167932   0.299  0.76478    
## collabTRUE:main_colorBlue             -0.086387   0.053453  -1.616  0.10612    
## collabTRUE:main_colorBrown            -0.025852   0.091344  -0.283  0.77717    
## collabTRUE:main_colorGray             -0.334800   0.124236  -2.695  0.00706 ** 
## collabTRUE:main_colorGreen             0.134577   0.123672   1.088  0.27656    
## collabTRUE:main_colorMulti-Color      -0.087244   0.108713  -0.803  0.42229    
## collabTRUE:main_colorOrange            0.160857   0.091839   1.752  0.07991 .  
## collabTRUE:main_colorPurple            0.055075   0.105454   0.522  0.60151    
## collabTRUE:main_colorRed               0.070942   0.083420   0.850  0.39513    
## collabTRUE:main_colorWhite             0.110080   0.047026   2.341  0.01927 *  
## collabTRUE:main_colorYellow            0.045307   0.155297   0.292  0.77049    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.4186 on 6093 degrees of freedom
## Multiple R-squared:  0.3851, Adjusted R-squared:  0.378 
## F-statistic: 54.51 on 70 and 6093 DF,  p-value: < 2.2e-16

## Analysis of Variance Table
## 
## Model 1: log_resale_price ~ brand + release_month + release_dow + wmns + 
##     collab + retro + kids + main_color + bin_wants + log_retail_price
## Model 2: log_resale_price ~ brand + release_month + release_dow + wmns + 
##     collab + retro + kids + main_color + bin_wants + log_retail_price + 
##     bin_wants:collab + log_retail_price:brand + collab:main_color
##   Res.Df    RSS Df Sum of Sq     F    Pr(>F)    
## 1   6117 1118.6                                 
## 2   6093 1067.8 24    50.809 12.08 < 2.2e-16 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Call:
## lm(formula = log_resale_price ~ collab + log_retail_price + bin_wants + 
##     brand + retro + release_month + release_dow + wmns + collab:bin_wants + 
##     log_retail_price:brand, data = sneakers)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -1.6163 -0.2313  0.0087  0.1751  3.7529 
## 
## Coefficients:
##                                        Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                            2.733536   0.129370  21.130  < 2e-16 ***
## collabTRUE                             0.114659   0.049252   2.328  0.01994 *  
## log_retail_price                       0.389646   0.026034  14.967  < 2e-16 ***
## bin_wantsSomewhat Popular             -0.023223   0.017589  -1.320  0.18677    
## bin_wantsVery Popular                  0.052436   0.018223   2.878  0.00402 ** 
## bin_wantsExtremely Popular             0.180985   0.019853   9.116  < 2e-16 ***
## brandAir Jordan                       -1.500470   0.276037  -5.436 5.67e-08 ***
## brandAsics                             5.534953   3.993674   1.386  0.16582    
## brandConverse                         -4.169570   1.911670  -2.181  0.02921 *  
## brandJordan Brand                     -1.045891   0.656973  -1.592  0.11144    
## brandNew Balance                      -4.481266   2.523946  -1.775  0.07587 .  
## brandNike                             -1.793524   0.162459 -11.040  < 2e-16 ***
## brandNike Basketball                  -2.197946   0.724823  -3.032  0.00244 ** 
## brandNike Running                     -0.983794   1.224816  -0.803  0.42188    
## brandOther Brands                      0.041601   0.897408   0.046  0.96303    
## brandPuma                              0.375869   1.056407   0.356  0.72200    
## brandReebok                           -0.319454   0.824582  -0.387  0.69846    
## retroTRUE                              0.163526   0.032267   5.068 4.14e-07 ***
## release_monthFeb                       0.027853   0.028986   0.961  0.33663    
## release_monthMar                       0.077363   0.028946   2.673  0.00755 ** 
## release_monthApr                       0.026515   0.029396   0.902  0.36710    
## release_monthMay                      -0.019191   0.030739  -0.624  0.53242    
## release_monthJun                       0.041827   0.029781   1.404  0.16022    
## release_monthJul                       0.017751   0.030354   0.585  0.55872    
## release_monthAug                       0.025042   0.030003   0.835  0.40394    
## release_monthSep                       0.069895   0.030961   2.258  0.02401 *  
## release_monthOct                       0.039128   0.031611   1.238  0.21584    
## release_monthNov                       0.085086   0.029963   2.840  0.00453 ** 
## release_monthDec                       0.082409   0.030361   2.714  0.00666 ** 
## release_dowMonday                      0.105823   0.035145   3.011  0.00261 ** 
## release_dowTuesday                     0.022403   0.032776   0.684  0.49430    
## release_dowWednesday                   0.021926   0.030088   0.729  0.46620    
## release_dowThursday                   -0.009759   0.026616  -0.367  0.71387    
## release_dowFriday                      0.007491   0.027830   0.269  0.78782    
## release_dowSaturday                    0.034916   0.027094   1.289  0.19755    
## wmnsTRUE                               0.026267   0.015809   1.662  0.09665 .  
## collabTRUE:bin_wantsSomewhat Popular   0.093380   0.058934   1.584  0.11314    
## collabTRUE:bin_wantsVery Popular       0.084190   0.058063   1.450  0.14712    
## collabTRUE:bin_wantsExtremely Popular  0.508422   0.061075   8.325  < 2e-16 ***
## log_retail_price:brandAir Jordan       0.328881   0.054844   5.997 2.13e-09 ***
## log_retail_price:brandAsics           -1.136952   0.795104  -1.430  0.15279    
## log_retail_price:brandConverse         0.906474   0.417630   2.171  0.03001 *  
## log_retail_price:brandJordan Brand     0.195821   0.134331   1.458  0.14496    
## log_retail_price:brandNew Balance      0.874204   0.499361   1.751  0.08006 .  
## log_retail_price:brandNike             0.375747   0.033291  11.287  < 2e-16 ***
## log_retail_price:brandNike Basketball  0.447987   0.140705   3.184  0.00146 ** 
## log_retail_price:brandNike Running     0.232884   0.252175   0.923  0.35578    
## log_retail_price:brandOther Brands    -0.012604   0.184143  -0.068  0.94543    
## log_retail_price:brandPuma            -0.132029   0.218608  -0.604  0.54590    
## log_retail_price:brandReebok           0.068942   0.167460   0.412  0.68058    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.4194 on 6114 degrees of freedom
## Multiple R-squared:  0.3807, Adjusted R-squared:  0.3757 
## F-statistic:  76.7 on 49 and 6114 DF,  p-value: < 2.2e-16
## 
## Call:
## lm(formula = log_resale_price ~ collab + log_retail_price + bin_wants + 
##     retro + collab:bin_wants, data = sneakers)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -1.7486 -0.2353  0.0000  0.1787  3.9516 
## 
## Coefficients:
##                                       Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                            1.63925    0.07945  20.632  < 2e-16 ***
## collabTRUE                             0.07159    0.04964   1.442 0.149312    
## log_retail_price                       0.63395    0.01698  37.341  < 2e-16 ***
## bin_wantsSomewhat Popular             -0.03505    0.01701  -2.061 0.039390 *  
## bin_wantsVery Popular                  0.05897    0.01714   3.440 0.000586 ***
## bin_wantsExtremely Popular             0.21847    0.01767  12.364  < 2e-16 ***
## retroTRUE                              0.19876    0.03155   6.300 3.19e-10 ***
## collabTRUE:bin_wantsSomewhat Popular   0.07812    0.05956   1.312 0.189690    
## collabTRUE:bin_wantsVery Popular       0.07705    0.05829   1.322 0.186251    
## collabTRUE:bin_wantsExtremely Popular  0.50417    0.06165   8.178 3.49e-16 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.4277 on 6154 degrees of freedom
## Multiple R-squared:  0.3517, Adjusted R-squared:  0.3508 
## F-statistic:   371 on 9 and 6154 DF,  p-value: < 2.2e-16
## Analysis of Variance Table
## 
## Model 1: log_resale_price ~ collab + log_retail_price + bin_wants + retro + 
##     collab:bin_wants
## Model 2: log_resale_price ~ collab + log_retail_price + bin_wants + brand + 
##     retro + release_month + release_dow + wmns + collab:bin_wants + 
##     log_retail_price:brand
##   Res.Df    RSS Df Sum of Sq     F    Pr(>F)    
## 1   6154 1125.7                                 
## 2   6114 1075.4 40    50.319 7.152 < 2.2e-16 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## Analysis of Variance Table
## 
## Model 1: log_resale_price ~ collab + log_retail_price + bin_wants + brand + 
##     retro + release_month + release_dow + wmns + collab:bin_wants + 
##     log_retail_price:brand
## Model 2: log_resale_price ~ brand + release_month + release_dow + wmns + 
##     collab + retro + kids + main_color + bin_wants + log_retail_price + 
##     bin_wants:collab + log_retail_price:brand + collab:main_color
##   Res.Df    RSS Df Sum of Sq      F   Pr(>F)   
## 1   6114 1075.4                                
## 2   6093 1067.8 21    7.6161 2.0695 0.002817 **
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##                                              2.5 %       97.5 %
## (Intercept)                           1.176620e+01 1.966458e+01
## brandAir Jordan                       1.324398e-01 3.962844e-01
## brandAsics                            1.338366e-01 8.643403e+05
## brandConverse                         4.840458e-04 8.763348e-01
## brandJordan Brand                     9.967784e-02 1.306241e+00
## brandNew Balance                      1.618964e-04 3.250112e+00
## brandNike                             1.219457e-01 2.307072e-01
## brandNike Basketball                  2.871492e-02 4.923019e-01
## brandNike Running                     3.407481e-02 4.139029e+00
## brandOther Brands                     1.782210e-01 6.103646e+00
## brandPuma                             1.316686e-01 8.558040e+00
## brandReebok                           1.592570e-01 4.075225e+00
## release_monthFeb                      9.699678e-01 1.086757e+00
## release_monthMar                      1.022194e+00 1.145166e+00
## release_monthApr                      9.675182e-01 1.085790e+00
## release_monthMay                      9.230073e-01 1.041289e+00
## release_monthJun                      9.831023e-01 1.104860e+00
## release_monthJul                      9.581985e-01 1.079259e+00
## release_monthAug                      9.679660e-01 1.088748e+00
## release_monthSep                      1.007962e+00 1.137958e+00
## release_monthOct                      9.784459e-01 1.107580e+00
## release_monthNov                      1.028946e+00 1.157187e+00
## release_monthDec                      1.023402e+00 1.152807e+00
## release_dowMonday                     1.032461e+00 1.185036e+00
## release_dowTuesday                    9.591209e-01 1.090720e+00
## release_dowWednesday                  9.667666e-01 1.087685e+00
## release_dowThursday                   9.388039e-01 1.042063e+00
## release_dowFriday                     9.555792e-01 1.065774e+00
## release_dowSaturday                   9.829524e-01 1.093124e+00
## wmnsTRUE                              9.948065e-01 1.059472e+00
## collabTRUE                            9.618569e-01 1.199861e+00
## retroTRUE                             1.103626e+00 1.252890e+00
## kidsTRUE                              9.415511e-01 1.029880e+00
## main_colorBlue                        9.731827e-01 1.040380e+00
## main_colorBrown                       9.028227e-01 1.048631e+00
## main_colorGray                        9.371387e-01 1.046281e+00
## main_colorGreen                       9.250752e-01 1.076311e+00
## main_colorMulti-Color                 9.998458e-01 1.181497e+00
## main_colorOrange                      8.709724e-01 1.012612e+00
## main_colorPurple                      9.032237e-01 1.044140e+00
## main_colorRed                         9.623995e-01 1.056666e+00
## main_colorWhite                       9.854352e-01 1.045143e+00
## main_colorYellow                      7.863189e-01 1.047039e+00
## bin_wantsSomewhat Popular             9.423282e-01 1.009768e+00
## bin_wantsVery Popular                 1.013673e+00 1.089080e+00
## bin_wantsExtremely Popular            1.148046e+00 1.241521e+00
## log_retail_price                      1.405697e+00 1.558695e+00
## collabTRUE:bin_wantsSomewhat Popular  1.003744e+00 1.266332e+00
## collabTRUE:bin_wantsVery Popular      9.973331e-01 1.254489e+00
## collabTRUE:bin_wantsExtremely Popular 1.498079e+00 1.907147e+00
## brandAir Jordan:log_retail_price      1.240162e+00 1.540905e+00
## brandAsics:log_retail_price           6.360763e-02 1.443149e+00
## brandConverse:log_retail_price        1.018993e+00 5.249431e+00
## brandJordan Brand:log_retail_price    9.294067e-01 1.572913e+00
## brandNew Balance:log_retail_price     7.829926e-01 5.558431e+00
## brandNike:log_retail_price            1.361099e+00 1.551150e+00
## brandNike Basketball:log_retail_price 1.172875e+00 2.035948e+00
## brandNike Running:log_retail_price    7.695449e-01 2.067337e+00
## brandOther Brands:log_retail_price    6.870602e-01 1.418858e+00
## brandPuma:log_retail_price            6.092268e-01 1.445018e+00
## brandReebok:log_retail_price          7.565723e-01 1.461488e+00
## collabTRUE:main_colorBlue             8.259890e-01 1.018569e+00
## collabTRUE:main_colorBrown            8.147132e-01 1.165576e+00
## collabTRUE:main_colorGray             5.608252e-01 9.127867e-01
## collabTRUE:main_colorGreen            8.977489e-01 1.457931e+00
## collabTRUE:main_colorMulti-Color      7.405521e-01 1.134137e+00
## collabTRUE:main_colorOrange           9.810038e-01 1.406204e+00
## collabTRUE:main_colorPurple           8.592863e-01 1.299269e+00
## collabTRUE:main_colorRed              9.115668e-01 1.264243e+00
## collabTRUE:main_colorWhite            1.018054e+00 1.224174e+00
## collabTRUE:main_colorYellow           7.717226e-01 1.418703e+00
##                       brandAir Jordan                            brandAsics 
##                            353.059584                           2182.109071 
##                         brandConverse                     brandJordan Brand 
##                            520.080647                            319.790886 
##                      brandNew Balance                             brandNike 
##                            400.075956                            232.428448 
##                  brandNike Basketball                     brandNike Running 
##                            401.539087                            272.226211 
##                     brandOther Brands                             brandPuma 
##                            451.504644                            365.287879 
##                           brandReebok                      release_monthFeb 
##                            372.539592                              2.698560 
##                      release_monthMar                      release_monthApr 
##                              2.758851                              3.063686 
##                      release_monthMay                      release_monthJun 
##                              2.352315                              2.510071 
##                      release_monthJul                      release_monthAug 
##                              2.383284                              2.524564 
##                      release_monthSep                      release_monthOct 
##                              2.231865                              2.108956 
##                      release_monthNov                      release_monthDec 
##                              2.391471                              2.320492 
##                     release_dowMonday                    release_dowTuesday 
##                              1.814133                              2.268680 
##                  release_dowWednesday                   release_dowThursday 
##                              2.704698                              4.628991 
##                     release_dowFriday                   release_dowSaturday 
##                              4.155572                              5.407437 
##                              wmnsTRUE                            collabTRUE 
##                              1.186176                             10.522385 
##                             retroTRUE                              kidsTRUE 
##                              1.116743                              1.227197 
##                        main_colorBlue                       main_colorBrown 
##                              1.441675                              1.304606 
##                        main_colorGray                       main_colorGreen 
##                              1.154905                              1.172617 
##                 main_colorMulti-Color                      main_colorOrange 
##                              1.256948                              1.305476 
##                      main_colorPurple                         main_colorRed 
##                              1.230762                              1.246164 
##                       main_colorWhite                      main_colorYellow 
##                              1.480763                              1.329789 
##             bin_wantsSomewhat Popular                 bin_wantsVery Popular 
##                              1.920047                              2.200202 
##            bin_wantsExtremely Popular                      log_retail_price 
##                              2.665832                              3.313898 
##  collabTRUE:bin_wantsSomewhat Popular      collabTRUE:bin_wantsVery Popular 
##                              3.729120                              4.252918 
## collabTRUE:bin_wantsExtremely Popular      brandAir Jordan:log_retail_price 
##                              3.187039                            357.990262 
##           brandAsics:log_retail_price        brandConverse:log_retail_price 
##                           2182.882839                            520.426173 
##    brandJordan Brand:log_retail_price     brandNew Balance:log_retail_price 
##                            319.826771                            400.074258 
##            brandNike:log_retail_price brandNike Basketball:log_retail_price 
##                            238.020203                            402.871264 
##    brandNike Running:log_retail_price    brandOther Brands:log_retail_price 
##                            272.192130                            451.642426 
##            brandPuma:log_retail_price          brandReebok:log_retail_price 
##                            364.962463                            372.424046 
##             collabTRUE:main_colorBlue            collabTRUE:main_colorBrown 
##                              1.839961                              1.421393 
##             collabTRUE:main_colorGray            collabTRUE:main_colorGreen 
##                              1.142537                              1.219088 
##      collabTRUE:main_colorMulti-Color           collabTRUE:main_colorOrange 
##                              1.344403                              1.436819 
##           collabTRUE:main_colorPurple              collabTRUE:main_colorRed 
##                              1.328049                              1.342645 
##            collabTRUE:main_colorWhite           collabTRUE:main_colorYellow 
##                              2.193171                              1.373942

## Linear mixed model fit by REML ['lmerMod']
## Formula: log_resale_price ~ (1 | brand) + release_month + release_dow +  
##     wmns + collab + retro + kids + main_color + bin_wants + retail_price
##    Data: sneakers
## 
## REML criterion at convergence: 7286.3
## 
## Scaled residuals: 
##     Min      1Q  Median      3Q     Max 
## -5.8785 -0.5723 -0.0271  0.4832  8.7730 
## 
## Random effects:
##  Groups   Name        Variance Std.Dev.
##  brand    (Intercept) 0.008084 0.08991 
##  Residual             0.184705 0.42977 
## Number of obs: 6164, groups:  brand, 12
## 
## Fixed effects:
##                              Estimate Std. Error t value
## (Intercept)                 4.0736543  0.0476133  85.557
## release_monthFeb            0.0213021  0.0297161   0.717
## release_monthMar            0.0547314  0.0296867   1.844
## release_monthApr            0.0192001  0.0301579   0.637
## release_monthMay           -0.0329924  0.0314958  -1.048
## release_monthJun            0.0284872  0.0304721   0.935
## release_monthJul           -0.0028104  0.0310392  -0.091
## release_monthAug            0.0217993  0.0307140   0.710
## release_monthSep            0.0668168  0.0317158   2.107
## release_monthOct            0.0417167  0.0324003   1.288
## release_monthNov            0.0916576  0.0306865   2.987
## release_monthDec            0.0709083  0.0310721   2.282
## release_dowMonday           0.1779192  0.0357938   4.971
## release_dowTuesday          0.0684542  0.0332779   2.057
## release_dowWednesday        0.0629387  0.0306676   2.052
## release_dowThursday         0.0472275  0.0269842   1.750
## release_dowFriday           0.0448672  0.0282779   1.587
## release_dowSaturday         0.0791715  0.0276000   2.869
## wmnsTRUE                    0.0336349  0.0164518   2.044
## collabTRUE                  0.2580805  0.0193282  13.353
## retroTRUE                   0.1511631  0.0329742   4.584
## kidsTRUE                   -0.0610148  0.0228466  -2.671
## main_colorBlue              0.0022677  0.0165131   0.137
## main_colorBrown            -0.0620913  0.0355652  -1.746
## main_colorGray             -0.0089108  0.0280363  -0.318
## main_colorGreen             0.0147141  0.0376136   0.391
## main_colorMulti-Color       0.0616943  0.0401102   1.538
## main_colorOrange           -0.0289575  0.0356443  -0.812
## main_colorPurple           -0.0233059  0.0353917  -0.659
## main_colorRed               0.0205475  0.0234084   0.878
## main_colorWhite             0.0272792  0.0145749   1.872
## main_colorYellow           -0.1027996  0.0658986  -1.560
## bin_wantsSomewhat Popular   0.0117084  0.0170289   0.688
## bin_wantsVery Popular       0.1137923  0.0175774   6.474
## bin_wantsExtremely Popular  0.3047638  0.0191639  15.903
## retail_price                0.0033335  0.0001014  32.859